1. Field of the Invention
The present invention relates to a vehicle body structure with a head protecting airbag wherein an airbag is provided on a back surface side of an automotive roof lining, wherein the roof lining is adapted to be dislocated from a rear pillar garnish by virtue of an expansion pressure resulting when the airbag is expanded, and wherein the airbag is allowed to expand into a passenger compartment through a gap so resulting between the rear pillar garnish and the roof lining.
2. Description of the Related Art
Pillar garnishes are provided on front pillars, center pillars and rear pillars which support a roof of an automobile as linings. Certain devices have been provided to have a good appearance at an abutment portion where each garnish abuts with another lining material. Known as an example of the devices is JP-B-63-6384 entitled “Automotive Trim Components Joining Portion Structure.”
Incidentally, a roof lining is provided to the roof supported by the respective pillars as a lining. There also needs to have a good appearance at portions where the roof lining is joined to the pillar garnishes, and it is a common practice in order to have a good appearance at the joining portions that the circumferential edge of the roof lining is caused to overlap the back surface side of the pillar garnishes so that the circumferential edge of the roof lining is concealed with the pillar garnishes.
There are some constructions in which an airbag for protecting the head of a passenger is provided on the back surface side of the roof lining. A vehicle body structure is shown in FIG. 8 in which an airbag is provided on the back surface side of a roof lining, and the details thereof will be described below.
FIG. 8 is a side view of a conventional vehicle body structure with a head protecting airbag.
In a vehicle body structure with a head protecting airbag 100, a frame portion 102 of a rear pillar garnish 101 is provided in such a manner as to extend along an upper portion of a rear side window glass frame member, a rear projecting portion 103 of the rear pillar garnish 101 is caused to project upwardly from a rear end of the frame portion 102 until the rear projecting portion reaches a rear window glass 104, a side portion 106 and a rear portion 107 of a roof lining 105 are caused to overlap a back surface of the frame portion 102 and a back surface of the rear projecting portion 103 of the rear pillar garnish 101, respectively, and a head protecting airbag 110 is provided within a space existing between the roof lining 105 and a vehicle body panel. Note that reference numeral 108 denotes a rear side window glass.
FIG. 9 is a side view showing a state in which an airbag of the conventional vehicle body structure with a head protecting airbag is expanded.
An inflator 111 for the head protecting airbag 110 is activated, and a gas is supplied to an airbag 113 from the inflator 111, whereby the airbag is expanded.
An expansion pressure is generated by the expansion of the airbag 113, and the side portion 106 of the roof lining 105 is dislocated from the frame portion 102 of the pillar garnish 101 toward the passenger compartment side with the expansion pressure, whereby a gap can be opened between the frame portion 102 of the pillar garnish 101 and the side portion 106 of the roof lining 105.
Thus, the airbag 113 can be expanded into the passenger compartment through the gap so opened so that the head of a rear seat passenger can be protected with the airbag 113 so expanded.
With the vehicle body structure with a head protecting airbag 100, however, as shown in FIG. 8, the rear portion 107 of the roof lining 105 is also caused to extend along the vehicle body panel only with the rear portion 107 being caused to overlap the back surface of the rear projecting portion 103 of the pillar garnish 101.
Due to this, in the event that the expansion pressure of the airbag 113 is applied to the rear portion 107 of the roof lining 105, it becomes difficult to securely support the rear portion 107 of the roof lining 105 with the rear projecting portion 103 of the pillar garnish 101, and as shown in FIG. 9, there may be caused a risk that the rear portion 107 of the roof lining 105 is dislocated from the rear projecting portion 103 of the pillar garnish 101 toward the passenger compartment side.
In the event that the rear portion 107 of the roof lining 105 is dislocated from the rear projecting portion 103 of the pillar garnish 101, there may be caused a risk that a gap is generated between the rear portion 107 and the rear projecting portion 103, whereby the airbag 113 is also expanded into the passenger compartment through the gap so generated.
Consequently, a vehicle body structure has been long desired to be put in a practical use in which in the event that the expansion pressure of the airbag 113 is applied, the airbag 113 can be expanded stably through the gap between the frame portion 102 of the pillar garnish 101 and the side portion 106 of the roof lining 105.